Apparatus for grinding and polishing plow-colters



(No Model.) Y

J. T. DUFF.

APPARATUS FOR GRINDING AND POLISHING PLOW OOLTERS, &c. No. 249,746. Patented Nov. 22,1881.

lnfrlrpz as E shVEJIlURA mgw,

N, PETERS. FhnloLxlhogmplmr. Washmglcn. D. C.

NITED STATES PATENT OFFICE.

JOHN T. DUFF, OF PITTSBURG, PENNSYLVANIA.

APPARATUS FOR GRINDING AND POLISHING PLOW-COLTERS,&.O.

9 SPECIFICATION forming part of Letters Patent No. 249,746, dated November 22, 1881.

Application filed March 30, 1881. (N model.)

T0 all whom it may concern: I

Be it known that I, JOHN T. DUFF, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Apparatus for Grinding and Polishing Plow-Golters, Saw-Blanks, and Similar Articles; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, forming a part thereof, in which- Figure 1 indicates a plan view of my improved grinding and polishing apparatus. Fig. 2 indicates an enlarged plan view of the mechanism for centering and holding the blank and controlling its forward and lateral movement during the grinding and polishing operation. Fig. Sindicates a cross-sectional elevation of the same, taken through at the line y y shown in Fig. 2. Fig. at indicates a plan view of a portion of the mechanism shown in Fig. 1, showingthe grinding and polishing wheels adjusted laterally for grinding and polishing at a dinerent angle.

Like letters of reference indicate like parts wherever they occur.

My invention relates to a new and useful apparatus for automatically grinding and polishin g colters and circular-saw blanks uniformly and at a single operation, wherein I proceed by mounting the blank upon a suitable mandrel and feeding it at varying angles between two grinding and polishing surfaces,which are adjusted to exert pressure, and a grinding and 1 polishing action on the sides of the blank,

while the rotary movement of the blank is regulated by means of suitable mechanism.

Heretofore, so far as I am aware, the common custom has been to grind and polish colter and circular-saw blanks by a series of separate and distinct grinding and polishing operations. In practice the blank was mounted or centered on a mandrel attached to abed having alforward and backward sliding movement, so as to bring the forward portion of the blank up between the face of the grindstone and a holding block or plate, which were ar-' ranged in front of the sliding bed. The grindstone was then forced against one of the sides of the blank. In this operation the blank was it was impossible to grind convex and concave surfaces, and the grinding operation could only be performed on blanks having plain sides by only doing one side at a time.

It is obvious that the method of grinding and polishing colter and saw blanks which I have described is slow, laborious, and costly, and that considerable time is lost in removing the blank from its holding devices in order to turn it for the succeeding grinding and polishing operations.

The object of my invention is to render the grinding and polishing operation continuous and automatic and adapted to produce a highly-polished surface on circular blanks having beveled edges, convex and concave sides, or irregular forms. v

I will now proceed to describe my invention in such a manner that others skilled in the art to-which it appertains may readily make and use the same.

In the drawings,Aindicates the frame upon which the grinding and polishing mechanism is mounted.

B and Bindicate slidingbeds provided with grooved sides, which engage the inwardly-projecting edgeszof the upper portion of the inner sides of the frame A in such a manner as to a1 low their easy sliding movement to and from each other, but not to admit of lateral play. 0 and cindicate adjusting-screws, journaled in the opposite ends of the upper portion of the frame A. The inner ends of these screws are attached to the outer ends of the sliding beds B and B, so that the beds may be moved to and from each other by the application of power to actuate the screws for that purpose.

G and G indicate supplementary beds mounted on the sliding beds B and B, and having central pivotal connections thereto by means of bolts g which pass up from the lower sliding beds. The forward and rear portions of each of these beds are slotted in the arcs of circles whose common center is the pivot-bolt 9 on which the supplemental bed turns, and

they are connected to the beds B and B at these portions by means of bolts, which pass up through the slotted portions to secure the upper bed from displacement during its lateral adjustment, or from the action of the grinding or polishing wheels. The rear of each rotating or supplemental bed G and G is usually provided with an arm or handle, g g, to facilitate the rotation of the bed upon its pivot, though other means may be employed, if desired.

D and D indicate shafts,journaled upon the upper or laterally-adjustable beds G and G. 'lhese shafts D D may be made of any desired length, according to the distance through which it is found desirable to move the grinding and polishing wheels E E by the rotation of the supplemental bed.

E E and E E indicate emery-wheels, suit ably mounted and keyed on the ends of their respective shafts, D and D. One set of these emery-wheels E E have a peripheral grindingsurface, 6, and a beveled edge, e, which latter is only used in grinding andpolishing concave surfaces. The shafts D and D are provided with pulleys F and F, for the purpose of transmitting power, by means of belting to the same, to cause the emery-wheels to rotate rapidly. I

A and A indicate the frames of the blank holding, centering, and adjusting mechanisms, which are provided respectively with sliding beds B and B the slotted sides of which engagetheinwardly-projecting edges of the sides of the frames A and A in order to admit the backward-and-forward movement of the beds by means ofpinionsp, actuated by hand-wheels P at the side of the frames, meshing into racks 10, formed upon the lower sides of the bottom of each of the sliding beds, as will be readily understood by an inspection of Figs. 1 and 3.

G- and G indicate supplementary beds mounted on the sliding beds B and B and connected thereto by a central pivotal connection, I). These supplemental beds are also provided with curved slots b h of which the pivot 12 is the center, in order that the supplementary beds may be moved in a lateral curvilineal line. The supplemental beds G G have longitudinal slots G, to receive the colterblank or saw-blank, as the case may be, and this slot Gr intersects the slot 0 .so that the slot 1) is practically composed of two open slots. This permits two binding-screws to be used in the slot 11 to secure the supplemental or rotating bed without interfering with its movement, and by locating the binding-screws about one-fourth the distance from each end of the slot the greatest possible motion of the bed G2 or G is permitted.

9 9 indicate handles, which may be used to rotate the beds Gr G H and 11 indicate rollers journaled in bearings on slidin g boxes 0 on the forward ends of the supplementary beds G and G and are adjusted to exert pressure upon the blank by means of set-screws mounted in suitable boxes resting on the sides of the forward portions of the beds G and G The inner ends of these screws are attached to the outer ends of the sliding boxes, and their outer ends are provided with hand'wheels It and h, in order that they may be actuated to force the rolls against the blank during the grinding and polishing operation. One end of the shaft of the roll H projects out slightly beyond the side of its sliding boxes, and is provided with a pulley, I, for the transmission of power to the roll H, in order to drive it, by means of belting, at a regular and uniform speed, so that when the rolls are adjusted to exert a pressure against the sides of the blank the frictional resistance of the roll H against the side of the blank will control and regulate its rotary movement during the grinding operation.

In order to support the blank and permit its rotation, a pintle, s, is provided on the end of one of the sliding boxes 0, as shown in Figs. 1 and 2.

The beds G and G3 are attached to the lower beds, B and B by means of bolts, which pass through slots formed in curved lines near the front and rear of the beds, which bolts aid the central pivotal connections in keeping the upper beds in position, and at the same time allow the lateral movement of the upper beds upon their central pivots.

The operation of my improvement, when grinding and polishing flat blanks, is as follows: The colter is mounted upon the pintle s at the forward end and center of one of the adjusting and holding mechanisms. The rollers H and H are then screwed up against the sides of the blank, to hold it in position on the pintle or mandrel. The adjusting mechanism is then brought forward by turning the handwheel P at the side of its frame, which, aetuat ing the rack and pinion, causes the upper portion of the mechanism to slide forward on the frame. The upper bed is then moved or rotated on its central pivotal connection to the lower sliding bed until the plane of the beveled edge of the colter is brought in line or coincides with the plane of the grinding-surface c on the periphery of the emery-wheel, and is gradually moved forward until all portions of the bevel have become ground and polished. The upper bed is then drawn back or rotated until the sides of the colter are on a line or coincide with the plane of the grinding-surface e or periphery of the polishing-wheels, when the holding mechanism is again carried forward until the sides of the colter enter between the polishing-surfaces, which are forced, by turning thejhand-wheels c and 0, up against the blank. The emery-wheels E E revolve to ward each other, or one from right to left and the other from left to right. Consequently the action of these wheels upon the blank which is between them causes it to rotate rapidly. In order to regulate this rotation so as to render the grinding operation uniform and efiicient,

the rollers H and H are tightened up until the frictional resistance of the roller which is driven by thepulley regulates the rotation of the blank to the point desired.

When it is desired to grind and polish concave or convex surfaces, where one side only of a eolter can be operated upon at a time, the blank is first arranged upon the pintle s of the blank-holding mechanism and clamped by the friction-rollers H H, as before specified. One of the sliding beds, B or B, of the grinding and polishing mechanism is drawn back so as to carry its grinding-wheels out of the way and permit a free adjustment of those that are employed. The rotating bed which carries the remaining or operating wheels is next turned upon its pivot so that the grinding and polishing wheel will stand at the desired angle to the sliding bed and the circumferential grindingsurl'ace will coincide with the surface to be operated upon. (See Fig. 4.) The blank is then fed forward to the grinding-surface by advancing the sliding bed and rotating the supplemental or pivoted bed G It will thus be seen that, as the holding and grinding mechanism have a rectilinear as well as a curvilinear movement and adjustment, plain, as well as beveled, concave, and convex surfaces, may be readily ground and polished. In polishing and grinding these shapes the emery-wheels must of course be formed with beveled edges, and should be adjusted to allow the forward and curved movement of the blank during the operation.

Having described my invention,what I claim, and desire to secure by Letters Patent, is

1. In a machine for grinding and polishing colters and like articles, the combination of two grinding and polishing wheels adjustable to and from each other and arranged in substantially the same plane to operate by their peripheries upon opposite surfaces of a blank, a blank-support adapted to support the blank motion, and suitable mechanism for causing the grinding and polishing rolls to revolve toward each other, substantially as and for the purpose specified.

2. In a machine for grinding colters and like articles, the combination of a grinding and polishing wheel journaled on a reciprocating and rotating bed with a pintle-support adapted to support and permit the rotation of the blank when acted on by the grinding-wheel, and one or more friction -rollers adapted to bear upon and retard the motion of the blank, substantially as and for the purpose specified.

3. In a machine for grinding and polishing colters and like articles, a pintle adapted to support and permit the rotation of a blank and friction-rollers adapted to bear upon the blank and retard its rotation, said elements mounted upon a reciprocating and rotating bed, in combination with each other and with a grinding and polishing wheel arranged to act by its periphery upon the surface of a blank mounted on the pintle, substantially as and for the purpose specified.

4. In a machine for grinding and polishing colters and like articles, the combination of sliding beds B B, each provided with a rotating bed, G G, and a grinding and polishing wheel, E E, journaled on the rotating bed, with the sliding bed B having a rotating supplemental bed, G and the adjustable frictionvrolls H H, mounted thereon, substantially as and for the purpose specified.

In testimonywh ereof I have hereunto set my hand.

n J OHN T. DUFF.

Witnesses:

FRANK M. REESE,

WALTER Rnnsn. 

